H100 Manuals into A 100

[Hoaxel]

Does anybody has an Idea if it would be possible to implantate the Manuals of a H100 into a A100 foamdestroyed? im only thinking arount, for here in Germany you may sometimes get a H for some bucks, but no parts for the A, Axel

[bnelson218]

Lots to consider here. Remember that the H's tone generator has more frequencies than the A. If you intend to use these you'll need to also transplant the TG and the drawbar rail. Regarding the vibrato scanner, I'm not sure if it will mount on the right side of the TG or not. I know that an X77's TG will accommodate a scanner, and it's supposed to be identical to an H's TG, so you'll need to do some investigating. And I'm not sure if there's room under the drawbar rail for the vibrato switch or not; something else you'll need to consider. If not, there will be an Arduino-based version of the vibrato/chorus selector switch which a friend of mine in Ireland and I are designing. Youll need complete service manuals for both instruments before starting. Also remember that you'll be going from waterfall-style keys to divingboard style. The A and H keybeds are not interchangeable so therefore the keys won't be either. Last!y, the difference in the matching transformers, and percussion keying, will present issues although I believe these issues can be solved. Hey, I think it's a cool project. Keep us posted on what you decide.

[enor]

Lots to consider here. Remember that the H's tone generator has more frequencies than the A. If you intend to use these you'll need to also transplant the TG and the drawbar rail.

Not really.

The fact that there are different numbers of frequencies is easily overcome simply by wiring up external foldback on the manual terminal strips; repeating the lowest octave one time (with some extra small resistors on the first octave terminals to realise the lower volume in the folded-back register) and wiring folded-back frequencies from the octave below to the topmost 5 terminals.

There are more busbars in the H-100 manuals than in the A-100 ones, but this doesn't need to be a problem. Unused ones can simply be left unconnected, but if it were me I'd ground one of the unused busbars and use it as a percussion trigger - that way you would get percussion that doesn't rob a drawbar when switched on.

The biggest issues, the way I see it, are:
* Do they physically fit?
* Wrong key type

Plus, the manual tapering might be different (I haven't found any data on that)

[kziss]

Hi Enor and Hoaxel.

The fact that there are different numbers of frequencies is easily overcome simply by wiring up external foldback on the manual terminal strips; repeating the lowest octave one time (with some extra small resistors on the first octave terminals to realise the lower volume in the folded-back register) and wiring folded-back frequencies from the octave below to the topmost 5 terminals.

I modified my H-111 organ by removing the extra TG notes 92 to 96 and replacing these with the folded back TG notes 80 to 84 so that the regular treble foldback heard on most other Hammond console organs is now produced, and this sounds much better than the "cheesy" sound produced by the extra TG notes 92 to 96.

I did this easy simple modification by unsoldering the five wires on the TG terminal strip that were soldered on to the TG note 92 to 96 terminal pins, and I then soldered these five wires on to the TG note 80 to 84 terminal pins which are immediately to the right of the TG note 92 to 96 terminal pins.

I have wired up 0.120 uf ( 120 nf) capacitors in parallel with the 0.250 uf red mylar capacitors of the TG notes 49 to 54, and I have wired up 0.056 uf (56 nf) capacitors in parallel with the 0.1 uf red mylar capacitors of the TG notes 55 to 91 so that the H-111 tonewheel generator sounds much more like a 60+ year old wax capped tonewheel generator in order to make my H-111 sound closer to the non tapered pre 1937 Model A or BC organs.

However even with the aged wax paper capacitor simulation with the corresponding characteristic drop off in the levels of the TG notes 49 and above, the folded back TG notes still sound too shrill with the 888888888 drawbar setting so therefore it is a good idea to wire up resistors in series with the five wires that are now soldered on to the folded back TG notes 80 to 84.

I think that on the original pre 1937 non tapered Model A and BC organs, the majority of the resistance wires are 15 ohms or 16 ohms, but I think that the resistance wires of the folded back TG notes are something like 24 ohms or thereabouts in order to avoid excessive shrillness, so therefore I might experiment with trying out resistor values such as 8 ohms or 15 ohms or 20 ohms in series with the five wires with the folded back TG notes 80 to 84 in order to try to reduce their excessive shrillness.

However there still is the issue of dealing with the shrill sounding folded back TG notes 85 to 91 so therefore I would need to open up the manuals so that I can access and add suitable value resistors in series with the internal resistance wires which carry the folded back TG notes 85 to 91.

If I were to do this, then I would also wire up 27 ohms resistors in parallel with the resistance wires of the top octave of the manuals of the 16 ft, the 5 1/3 ft and the 8 ft drawbars in order to create the combined resistance of around 10 ohms like as they are in the tapered manuals so that this will then produce the fatter sounding top octave with the 16 ft, the 5 1/3 ft and the 8 ft drawbars as heard on the organs with the manual tapering.

On the non tapered organs, the top octave of the manuals of the 16 ft, the 5 1/3 ft and the 8 ft drawbars do sound a little anemic and overpowered by the higher drawbars, thus resulting in a thinner or more brittle sound, especially when using the overdriven organ sound.

There are more busbars in the H-100 manuals than in the A-100 ones, but this doesn't need to be a problem. Unused ones can simply be left unconnected, but if it were me I'd ground one of the unused busbars and use it as a percussion trigger - that way you would get percussion that doesn't rob a drawbar when switched on.

On the H-100 manuals there already is a busbar specifically for the percussion triggering so therefore you can use this busbar without having to ground out any of the drawbar busbars so therefore you can have the percussion effect without having to lose any drawbar.

In the H-100 manuals there are sixteen busbars inside the upper manual and twelve busbars inside the lower manual thus allowing other modifications such as using a busbar and it's corresponding keycontacts to be used for a MIDI application for synthesizers without having to sacrifice the drawbars. For example you could use the Brush Cymbal busbar and keycontacts in the upper manual and in the lower manuals for the Midi application.

The biggest issues, the way I see it, are:
* Do they physically fit?
* Wrong key type

One major problem with fitting H-100 manuals into an A100 organ is the fact that the H-100 manuals are a little longer than the A100 manuals so therefore they will not fitr inside the A100.
The extra length appears to be in order to accomodate the eight extra drawbars that are on the H-100. Both the left side cheekblocks and the right side cheekblocks are wider than the regular sized cheekblocks used on the A100 manuals.

The eight extra drawbars on the H-100 manuals also means that there is not enough space to fit the A100 Volume/Soft tablet and the two Vibrato Chorus control tablets on the left side and the four A100 percussion control tablets on the right side of the drawbars.

I do not know if there is enough clearance inside the far left side and inside the far right side of the H-100 manuals to allow you to saw off the excessive length of the metal assembly at the far left side and the far right side of the H-100 manuals so that they can then fit inside the A100 organ.

There would also be problems with positioning the large A-100 Vibrato /Chorus switching assembly box underneath the H-100 drawbar assembly plate.

However it might be possible to work out a way to mount the existing A100 long black drawbar assembly plate along with the A100 drawbars and the seven white tablet switches and the vibrato switching assembly box on top of the H-100 manuals in a similar manner as it is mounted on the A100 manuals, but I assume that you will need to drill and tap new screw holes or cut new bolt holes for this because the H-100 manuals have thin metal sides on the far left and the far right side whilst the A100 manuals have the thick wooden sides with the bolt holes and the screw holes present there.

As well as that, when viewed from above, the H-100 manuals are not as deep (or wide from front to back) as the A100 manuals are because on the H-100 manuals, the upper manual and the lower manual are spaced in such as way that the lower manual is further in underneath the upper manual so that the upper manual keys overlap over the lower manual and the upper and the lower manual are closer together with a narrower middle black metal rail than what is the case on the A100 manuals so therefore a lot of work would be needed to set up and install the H-100 manuals into the A100 organ.

The H-100 manuals will also need to be defoamed and the resistance wires then examined to see if there are any corroded wires which will need to be repaired.

* Wrong key type

I remember a long time ago reading about someone who successfully replaced the diving board keys with waterfall keys but unfortunately I do not have a copy of this information.

I do not like the fragile, easily broken diving board keys and the waterfall keys do look much nicer so therefore I am interested in knowing about this modification, especially as I would like to one day eventually get around to actually building a simplified portable "chop" organ using my spare H-100 manuals and my 1940's drawbar matching transformer and my Trek II SSP3A preamp along with the H-111 tonewheel generator and the Vibrato scanner..

Plus, the manual tapering might be different (I haven't found any data on that)

The H-100 series manuals are not tapered in the way that the post 1937 console organs (including the -3 series organs) are tapered, however judging by listening to the same particular TG notes as they appear on different drawbars of my H-111 organ, I can hear slight differences in the volume levels which indicates that there is some subtle form of manual tapering, or perhaps the slight differences in the volume levels might possibly be the result of differing tolerances in the actual resistance wires that were used instead of this being an intentional subtle form of manual tapering.

All the best.
Kon.

[peterb_2795]

.. A100 foam destroyed? ... but no parts for the A, Axel

Hi Axel,

Another side to this is whether you have the time,inclination or desire to repair the foam destroyed manual(s). I would imagine that Germany is as barren (and/or as expensive) as Australia in terms of acquiring replacement console manuals.

However, if you have the time, patience and desire, there are only a *mere* 549 key contacts to apply resistors to and then hook normal wire up between them and their respective frequency lugs... I know of at least one hammond nut in AU that has taken this route!

Photos: do this *only* if you have the time and patience !! (not recommended)

[Hoaxel]

Hi Peterb, your former Post " NEVER mix wine, heat and Hammond plastics" was amusing and instruktive, last autumne I fetched an H100 from Switzerland nearby in p arts. The
owners of the house changed the stairway to cellar a way ,the orgean was impossible to get out. High voltagewiring was bad, insulation broken away and a lot of strange"repairs", so I decided to make it spareparts.
There would have been your Plastics and keykontakts if I would have known your requirement. 200 Keykontakts are still here for the next time;-) I disassembled everything, even the manuals, and most parts found someone to use them.

Kons ideas are the way I thought about either, some metalwork is no problem. It seems, the change of the keys is the problem, the position of the manuals could be changed a bit to each other to get the waterfallposition,best way is, to see it side by side, Thanks a lot, Axel

[andyg]

Excellent, informative post, Kon, as always!

But I can I speak up for the many people who like the H just as it is, don't consider it in the slightest bit cheesy, have never, ever broken one of those 'correct organ style keys', and think it beats the c**p out of the B3! If only it were a bit more reliable....

Each to their own! :D